#

# Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

# All rights reserved.

# This component and the accompanying materials are made available

# under the terms of the License "Eclipse Public License v1.0"

# which accompanies this distribution, and is available

# at the URL "http://www.eclipse.org/legal/epl-v10.html".

#

# Initial Contributors:

# Nokia Corporation - initial contribution.

#

# Contributors:

#

# Description: 

#

#****h*	lib/xml2tree.pm

#	NAME

#		xml2tree.pm

#	DESCRIPTION

#		This module	is used	to parse the data	from a xml file and convert it to tree like data structure for further processing

#  		Each node is connected two way and looks like as follows

#	   +---------+------+------------+------------+--------------+----------------------+

#	   |prev			|el_name	 |attr		  |value	  	 |next               	|

#	   |(Reference to 	|(Name of    |(Hash of the|(String value)|Reference of array to	|

#	   |the parent node)|the element)|atrributes) |		         |next child elements)	|

#	   +----------------+------------+------------+--------------+----------------------+	 

#	RETURN VALUE

#   	0 if successfull, 1 on error

# 	EXAMPLE

#		use xml2tree;

#		.

#		.

#   	my $pr = xml2tree->new();

#		$pr->parseFile(dct5_release_note.xml);

#		.

#		.

#		my $trees = $getNode('Document');

#	SEE ALSO

#		sbt/data//subcon/dct5_release_note.xml

#   	sbt/make_dct5_upload.pl

#   	sbt/lib/sbt_common.pm

#	HISTORY

#		Version			:	0.1

#		Date				:	

#		Author			:	rownak

#   TODO

#		Case insensitive search

#		Support non recursive search in case of attachment

#******

package	xml2tree;

use	strict;

use	XML::Parser;

my %entities = ();

my %root;

my $parser;

my $curr_elem;

my $xml_file;

my $count=0;

#my @found_nodes;

#==========================================================

#		Intialization Part

#

#		Constructor. and others

#==========================================================

#usage(); 

#exit 0;

sub	new{

	$parser	= new	XML::Parser(ParseParamEnt	=> 1,Handlers	=> 

				{Entity	=> \&entityHandler,	

				 Char	=> \&charHandler,

				 Start =>	\&startHandler,

				 End =>	\&endHandler});

}

#   Parse a given XML file.

sub parseFile{

     my $file = shift; 

     $parser->parsefile($file);

}		

#==========================================================

#		Data Processing Part

#

#		

#==========================================================

#   XML::Parser uses this function when it finds  an xml entity.

sub entityHandler{

    my ($p, $name, $val) = @_;

    eval {$entities{$name} = $val;};

    die ("Error in handling xml characters " .

        "at line $p->current_line") if $@;

}

#   XML::Parser uses this function when it finds an xml element start entry.

sub startHandler{

    my ($p, $element, %attr) = @_;

    #Root of the tree

    if($element eq ''){

    	return;

	}

	$p->{cdata_buffer}='';

	#making a two way linked list of tree value

	if(not defined($curr_elem)){

    	$root{'el_name'} = $element;

    	$root{'attr'} = \%attr;

    	$root{'prev'} = 0;

    	$root{'next'} = 0;

    	$root{'value'}= 0;

    	$curr_elem = \%root;

    }else{

	   	my %element;

		$element{'el_name'} = $element;

		$element{'attr'} = \%attr;

		$element{'prev'} = $curr_elem;

		$element{'next'} = 0;

		$element{'value'}= 0;

		if($curr_elem->{'next'} == 0){

			my @child_element;

			push(@child_element,\%element);	

			$curr_elem->{'next'}=\@child_element;

		}

		else{

			my $child_element = $curr_elem->{'next'};

			push(@$child_element,\%element);	

			$curr_elem->{'next'}=$child_element;

		}

		$curr_elem = \%element;

   	}

}

#   XML::Parser uses this function when it finds  an xml element end entry.

sub endHandler{

	my($p) = @_;

	$curr_elem->{'value'} = $p->{cdata_buffer} ;

	$curr_elem = $curr_elem->{'prev'};

}

#   XML::Parser uses this function when it finds an xml character entry.

sub charHandler{

	my ($p, $str) = @_;

    my $element;

    my @context = $p->context;

    $str =~ s/^\s+//;

    $str =~ s/\s+$//;

	if($str eq ""){

		return;

	}

	$p->{cdata_buffer} .= $str;

}

##==========================================================

##		External interface part

##

##		This methods will be used by its client

##==========================================================

#

sub usage

{

    print"\n\n";

    print "Functionality: \n";

    print"======================\n";

    print "it parse any xml and convert the data into a two way trre like linked list \n\n";

    print "use xml2tree\n";

	print "\.\n";

	print "\.\n";

   	print 'my $pr = xml2tree->new()'."\n";

	print '$pr->parseFile(dct5_release_note.xml)'."\n";

	print "\.\n";

	print "\.\n";

	print 'my $trees = $getNode(\'Document\')'."\n";

}

#Depending on the search criteria it returns array of nodes.

# Input is 

# 	el_name    => element name of searching node(compulsory)

# 	attributes => Hash input of attributes to be searched. It will retun true even if it is a subset.(optional)

# 	value      => value of the element(optional)

#

#Output is 

#	Array of nodes that has been found . Each node has following type of structure

#	   +---------+------+------------+------------+--------------+----------------------+

#	   |prev			|el_name	 |attr		  |value	  	 |next               	|

#	   |(Reference to 	|(Name of    |(Hash of the|(String value)|Reference of array to	|

#	   |the parent node)|the element)|atrributes) |		         |next child elements)	|

#	   +----------------+------------+------------+--------------+----------------------+	 

sub getNode{

	my $tmp_el_name  = shift;

	my $tmp_attr     = shift;

	my $tmp_value    = shift;

	my @found_nodes=();	

	if ($tmp_el_name eq '0' ){

		return;	

	}

	if(not defined $tmp_attr){$tmp_attr=0;}

	if(not defined $tmp_value){$tmp_value=0;}

	searchTree($root{'next'},$tmp_el_name,$tmp_attr,  $tmp_value,\@found_nodes);

	return \@found_nodes; 

}

sub getPrevSibling{

	my $curr_element = shift;

	my $parent = $curr_element->{'prev'}; 	

	my $child_array = $parent->{'next'};

	my $prevSibling=undef;

	foreach my $tmp_sibling (@$child_array){

		if ($tmp_sibling == $curr_element){

			last;	

		}

	} 

	return $prevSibling

} 

sub getEntities{

	return \%entities;

}

sub getRoot{

	return \%root;

}

##==========================================================

##		Private functions part

##

##		This functions  will be used by external interface part

##==========================================================

#

sub searchTree{

	my $xml_sub_tree = shift;

	my $tmp_el_name  = shift;

	my $tmp_attr     = shift;

	my $tmp_value    = shift;

	my $found_nodes_ref = shift;

	my $is_attr_exist = 0; 

	my $is_value_exists=0;

	my $is_el_name_exists=0;

	if($xml_sub_tree eq '0'){return;}

	foreach my $node (@$xml_sub_tree){

		my $prev_node = $node->{'prev'}; 

		my $tmp_attr_node= $node->{'attr'};

		if($tmp_attr ne '0'){

			$is_attr_exist = is_LsubsetR($tmp_attr,$tmp_attr_node); 

		}

		if((($tmp_el_name eq '0')||(($tmp_el_name ne '0') && ($node->{'el_name'} eq $tmp_el_name))) &&

			(($tmp_value eq '0')||(($tmp_value ne '0') && ($node->{'value'} eq $tmp_value)))&&

			(($tmp_attr eq '0')||(($tmp_attr ne '0') && $is_attr_exist))){

			push (@$found_nodes_ref, $node)		

	    }

		searchTree ($node->{'next'}, $tmp_el_name, $tmp_attr, $tmp_value, $found_nodes_ref);

	}

}

sub is_LsubsetR(){

	my $left_hash  = shift;

	my $right_hash = shift;

	if ((keys(%$left_hash) == 0) || (keys(%$right_hash) ==0)){

		return 0;	

	}

	my $is_match=1;

	my $is_match_single;

	while(my($key, $value) = each(%$left_hash)){

		$is_match_single=0;

		while(my ($r_key,$r_value) = each(%$right_hash)){

			if(($key eq $r_key ) && ($value eq $r_value)){

				$is_match_single=1;

			}

		}

		$is_match = $is_match & $is_match_single;

	} 

	return $is_match;

}

1;